Method for improving caustic ratio of Barer process seeded precipitation mother solution

Abstract

The invention which discloses a method for improving the caustic ratio of a Barer process seeded precipitation mother solution relates to an improvement of a technology for producing alumina through a Barer process. The method is characterized in that lime is added to the Barer process seeded precipitation mother solution and subjected to a reaction, filter separation is carried out, the resulting separated filtrate is evaporated through an evaporation procedure, the evaporated filtrate is used to dissolve out a next batch of bauxite as a cycle mother solution, and a solid phase is separated through flushing with the cycle mother solution to a pre-desilicication adjustment tank to adjust the solid content in a desilicication slurry. The method of the invention, which allows calcium aluminate to be generated through adding lime to the Barer process seeded precipitation mother solution and reacting with a sodium aluminate solution, enables the concentration of alumina in the seeded precipitation mother solution to be reduced, so the caustic ratio of the seeded precipitation mother solution is improved, and a Barer process cycle efficiency improvement purpose is reached. Calcium aluminate generated in the reaction is settled and filtered, returns to the Barer process production flow, and is added to the pre-desilicication adjustment tank to substitute parts of lime. Energy consumed by evaporating the low-alumina-concentration seeded precipitation mother solution can be reduced.

Description

technical field [0001] The invention discloses a method for increasing the causticity ratio of the mother liquor of the Bayer method, and relates to an improvement of a process for producing alumina by the Bayer method. Background technique [0002] With the rapid development of the alumina industry, bauxite resources are becoming less and less, and the grade is constantly declining. The benefits of alumina enterprises are constantly declining, the production technical indicators are getting worse, and the cost is rising, which seriously restricts the development of enterprises. Optimizing the production process, improving process indicators, increasing production efficiency, and reducing production consumption have become important ways to improve the competitiveness of enterprises. [0003] At present, when the bauxite grade drops below the aluminum-silicon ratio of 5, there will be continuous problems in the production processes of the Bayer process, the normal pr...

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Problems solved by technology

[0003] At present, when the bauxite grade drops below the aluminum-silicon ratio of 5, there will be continuous problems in the production processes of the Bayer process, the normal production will be greatly affected, and the process indicators will decline. In particular, the cycle efficiency of the Bayer process will be changed from the original 160kg / m 3 Reduced to the current 130kg / m 3 Left and right, the alumina output rate is reduced, and the production efficiency is reduced

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